Truing and straightening gage for bicycle-forks



(No Model.)

. R. JOHNSTON.

TRUING AND STRAIGHTENING GAGE FOR BICYCLE FORKS. No. 591,277.

Patented Oct. 5,1897.

IEER M h W a awe (Mag.

Nrrn STATES- I P T TRUING AND STRAIGHTENING GA GE FOR BICYCLE-FORKS.

SPECIFICATION forming part of Letters Patent No. 591 ,277, dated October 5, 1897.

Application filed June 5, 1897. $erialNo. 639,527- (l T model.)

To all whom/it may concern.-

Be it known that LROBERT J oHNsToN,a citi zen of the United States, residing at Wilkes- Barr, in the county of Luzerne and State of Pennsylvania, have invented certain new and useful Improvements in Truing and Straightening Gages for Bicycle-Forks and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to'make and use the same.

This invention relates to a truing and straightening gage for bicycle-forks.

The object of this invention is to provide a simple and effective device for use in quickly and accurately truing and straightening bent or twisted bicycle-forks.

My device is more in the nature of a gage for showing the amount of abnormal twist or bend in anypart of the bicycle-forks, and for accurately showing when the part or parts have been bent or reduced to their normal shape, and is adapted for use with long or short forks and those of a different rake or curve. r

Iwill now describe the details of construction of my improved device by reference to the accompanying drawings, in whichthe other side.

Figure 1 represents aside perspective view showing bicycle-forks clamped in position. Fig. 2 represents a front end view slightly in perspective. Fig. 3 represents a transverse section of the chuck. Fig. 4 represents a vertical longitudinal section of the truing-gage on enlarged scale. Fig. 5 is a sectional view of the truing-gage.

The chuck A for holding the stem of the fork may be held in any vise, or otherwise secured to a suitable base, and is composed of the lower block a and the clamping-cap a,

each of which is provided at their adjacentfaces with a semicircular longitudinal groove Z) I) to form a bearing for the stem of the forks. The block and caparealso provided with the lateral lugs c c on one side and c on the other side, which have screw-threaded openings for the clamping-screws d d on one side and d on Between the adjoining faces of the block a and its cap a are placed spiral or other springs h, which may be held either in the block or cap, as preferred, for quickly raisin g the cap from the block when the clamping-screws are turned outward. The cap a :might be hinged or pivotally connected to the block, and a swinging screw-bolt provided with a nut used for clamping it to the block, for the purpose of engaging and holding the stem of the fork. The under side of the block a is provided with a deep longitudinal groove or slot a for receiving the lever-arm G, which is pivotally connected at the rear end of the groove by a pin g.

.. The squaring-gage E is hinged or pivotally connected near the rear end of the lever-arm G and a short distance in front of the chuck,

as'shown in Fig. 1, and is composed of the transverse pin 6, passing through the arm G and having at its outer end eyes for receiving the uprights e of the gage. The top bar e". of the gage is perfectly straight and horizontal when in position. ards e may be screw-threaded at their lower ends, as shown, and secured in the eyes of the transverse pins 6 by'means of nuts, but my invention is not confined to these details of construction. Evidently the gage may be made of a single casting composed of the uprights 6 and top bar 6'', the uprights having holes at their lower ends for the insertion of the transverse pin through them and through the hole in the bar. 1 I

The truing-gage F is provided with a transverse opening adapted to receive the arm G and slide lengthwise thereon, and can be held in any desired position by means of the thumbscrew f. The horizontal body portion of the gage F is provided with a longitudinal channel, into which is set'a right and left hand screw n, having at one end the hand-wheel f; also with a longitudinal slot. Upon the right and left hand screw 71 are placed the movable ja'wsM, passing through the slot and having vertical faces on and horizontal shoulders m to form bearings for the ends of the fork. My invention is not limited to thedetails of construction of the truing-gage here shown, but such device may be materially modified without departing from my invention, the'essential feature being the adjustable jaws, adapted to be moved outward or inward and set in any desired position on a body portion, which latter may be adjusted upon the lever-arm G.

The device may be operated as follows: The fork-stem isinclosed in a sleeve 0, of wood Theuprights or stand-- or other suitable material, and placed in the chuck. Before the stem is clamped in position the squaring-gage E is set with its uprights at right angles to the lever-arm G, and the arm is then raised, bringing the squaringgage E up against the fork, and the latter is at the same time so adjusted that the crown will lie fiat upon the horizontal bar 6 of the gage and parallel with the body of the truinggage. Then the stem is securely clamped in the chuck. The crown p of the fork will now be exactly parallel with the body of the truing-gage F. The squaring-gage E is then turned down upon the arm G. The truinggage F is then set in position directly under the ends of the fork, and the jaws M moved inward or outward by the hand-wheel f to the proper width of the fork ends. The outer end of arm G can now be swung upward, and in case the fork ends do not touch the two faces m m and the shoulders m m of the jaws the arm G is lowered and the fork sprung or bent in the necessary direction. This bend- 1 ing and twisting is repeated until the fork ends simultaneously touch the vertical faces m m and the horizontal shoulders m m of the jaws,when the forks will be perfectly true.

The pivoted arm G is readily adjustable to forks of different rake or curve by being raised or lowered at the outer end without removing the fork from the chuck. It is a novel and important feature of my device. By means of the squaring-gage E the forkcrown may be instantaneously and accurately adjusted parallel with the truing-gage.

The truing-gage being adjustable lengthwise on the arm G is adapted for use with long and short forks, and since the jaws M are quickly adjusted transversely by the right and left hand screw any bend or twist in the fork is quickly detected.

The chuck A is quickly operated by the screw (1' and the cap-screws (Z (Z, and the cap will be automaticallyraised when the screw is released by the springs 7L, thus facilitating the removal of the fork-stem.

I have found in practice that this device may be handled quickly and effect a saving of about eighty per cent. of the time required by ordinary methods and means in use for truing and straightening bicyele-forks.

Having described my invention, what I claim, and desire to secure by Letters Patent, 1s

1. In a gage for truin g and straightcningbicycle-forks, the combination with a clampin g-chuck, of a pivoted lever-arm adapted to be swung in a vertical plane, and an adj ustable squaring-gage connected to said arm and having a transverse top bar, adapted to be adjusted under the crown of the bicycle-fork, substantially as described.

2. In a gage fortruin g and straightening bicycle-forks, the combination with the clamping-chuck, of a squaring-gage for the forkerown and an adjustable truing-gage having jaws for bearing against the fork ends, substantially as described.

3. In agage fortruing and straightening bicycle-forks, the combination with the clamping-chuck, for holding the stem of the fork, of a pivoted lever-arm, a squaring-gage on said arm, adapted to bear against the crown of the fork, and a truing-gage adj ustable on said arm, and having adjustable jaws, substantially as and for the purpose described.

at. The combination with the clampingchuck, of a lever-arm pivoted thereto, a squaring-gage pivotally connected to said arm near the chuck and an adjustable truing-gage on the arm and having movable jaws, provided with vertical and horizontal bearing-surfaces, substantially as and for the purpose described.

5. In a gage for truing and straightening bicyele-forks, the combination with the clamping-chuck, for holding the stem of the fork, of a truing-gage having adjustable jaws for bearing upon the ends of the fork, and means for squaring the fork or adjusting the crown thereof parallel with said truing-gage, substantially as described.

6. In a gage for truing and straightening bicycle-forks, the combination with the clampin g-chuck for holding the stem of the fork, of a lever-arm pivoted thereto and adapted to be swung in a vertical plane, and a truing-gage adjustable longitudinally on said arm, and having transversely-adjustable jaws forbearing upon the ends of the fork, whereby the gage is adapted for truing forks of different rake or curve and of different length, substantially as described.

'7. In a gage for truing and straighteningbicycle-forks, the clamping-chuck having a longitudinal slot in its under side, in combination with a lever-arm pivoted in said slot, an adjustable truing-gage having transverselymovable jaws on said lever-arm, and means for squaring the fork or arranging its crown parallel with said truing-gage, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

ROBERT JOHNSTON.

Vi tnesses:

WILLARD G. Kunnx, 7M. J. TREMBATH. 

